1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <openssl/evp.h>
18
19#include <sys/types.h>
20#include <errno.h>
21#include <fcntl.h>
22#include <stdio.h>
23#include <stdlib.h>
24#include <string.h>
25#include <unistd.h>
26
27/**
28 * Simple program to generate a key based on PBKDF2 with preset inputs.
29 *
30 * Will print out the salt and key in hex.
31 */
32
33#define SALT_LEN 8
34#define ROUNDS 1024
35#define KEY_BITS 128
36
37int main(int argc, char* argv[])
38{
39    if (argc != 2) {
40        fprintf(stderr, "Usage: %s <password>\n", argv[0]);
41        exit(1);
42    }
43
44    int fd = open("/dev/urandom", O_RDONLY);
45    if (fd < 0) {
46        fprintf(stderr, "Could not open /dev/urandom: %s\n", strerror(errno));
47        close(fd);
48        exit(1);
49    }
50
51    unsigned char salt[SALT_LEN];
52
53    if (read(fd, &salt, SALT_LEN) != SALT_LEN) {
54        fprintf(stderr, "Could not read salt from /dev/urandom: %s\n", strerror(errno));
55        close(fd);
56        exit(1);
57    }
58    close(fd);
59
60    unsigned char rawKey[KEY_BITS];
61
62    if (PKCS5_PBKDF2_HMAC_SHA1(argv[1], strlen(argv[1]), salt, SALT_LEN,
63            ROUNDS, KEY_BITS, rawKey) != 1) {
64        fprintf(stderr, "Could not generate PBKDF2 output: %s\n", strerror(errno));
65        exit(1);
66    }
67
68    printf("salt=");
69    for (int i = 0; i < SALT_LEN; i++) {
70        printf("%02x", salt[i]);
71    }
72    printf("\n");
73
74    printf("key=");
75    for (int i = 0; i < (KEY_BITS / 8); i++) {
76        printf("%02x", rawKey[i]);
77    }
78    printf("\n");
79}
80